package cn.huhst.cas.weisiqian.web;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.log4j.Logger;

@WebServlet("/CheckCode.do")
public class CheckCode extends HttpServlet {
	private static final long serialVersionUID = 1L;
	private Logger logger = Logger.getLogger(CheckCode.class);

	public CheckCode() {
		super();
	}

	protected void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doPost(request, response);
	}

	protected void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		logger.debug("开始创建验证码图片");
		response.setContentType("image/jpeg");
		response.setHeader("Pragma", "No-cache");
		response.setHeader("Cache-Control", "no-cache");
		response.setDateHeader("Expires", 0);
		HttpSession session = request.getSession();

		int width = 60, height = 20;
		BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

		Graphics g = image.getGraphics();

		Random random = new Random();

		g.setColor(getRandColor(200, 250));
		g.fillRect(0, 0, width, height);

		g.setFont(new Font("Times New Roman", Font.PLAIN, 18));

		g.setColor(getRandColor(160, 200));
		for (int i = 0; i < 155; i++) {
			int x = random.nextInt(width);
			int y = random.nextInt(height);
			int xl = random.nextInt(12);
			int yl = random.nextInt(12);
			g.drawLine(x, y, x + xl, y + yl);
		}

		String sRand = "";
		for (int i = 0; i < 4; i++) {
			String rand = String.valueOf(random.nextInt(10));
			sRand += rand;
			g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));
			g.drawString(rand, 13 * i + 6, 16);
		}
		session.setAttribute("checkcode", sRand);
		logger.debug("本次请求创建的验证码为：" + sRand);
		g.dispose();
		ServletOutputStream responseOutputStream = null;
		try {
			responseOutputStream = response.getOutputStream();
		} catch (IOException e) {
			logger.debug("responseOutputStream = response.getOutputStream();获取返回流失败", e);
		}
		try {
			ImageIO.write(image, "JPEG", responseOutputStream);
		} catch (IOException e) {
			logger.debug("ImageIO.write(image, \"JPEG\", responseOutputStream);写出验证码失败", e);
		}

		try {
			responseOutputStream.flush();
		} catch (IOException e) {
			logger.debug("清空缓冲区出错");
		}
		try {
			responseOutputStream.close();
		} catch (IOException e) {
			logger.debug("关闭返回流出错 ");
		}
		logger.debug("结束创建验证码图片");
	}

	Color getRandColor(int fc, int bc) {
		Random random = new Random();
		if (fc > 255)
			fc = 255;
		if (bc > 255)
			bc = 255;
		int r = fc + random.nextInt(bc - fc);
		int g = fc + random.nextInt(bc - fc);
		int b = fc + random.nextInt(bc - fc);
		return new Color(r, g, b);

	}

}
